Sep 8, 2012 8:00am EDT
greatest cluster which has occurred, certainly, in the united states, that i'm aware of. >> reporter: so far, eight people have come down with the hantavirus. three of them have died in states as far flung as california, pennsylvania and west virginia. and there could be more cases as far away as france. the main outbreak traced to the popular curry village campsite, where rodents burrowed into tents. now, a second campsite in tuolomne. warnings like these went out to 10,000 people who visited curry village since june. late this week, notices went out to an additional 19 visitors at tuolomne visitors. 29,000 park visitors in all, all being warned about the hantavirus symptoms. they include fever, fatigue, and chills at first. they quickly give way to coughing, breathing problems as the lungs filled with fluid. and tourists are worried. >> i had a mouse run across my head. scared me pretty good. >> the only way for someone to contract hantavirus, is by breathing in particles of mouse feces and fluid. and it has to be an inclosed area, somewhere where there's not a lot of ventilation.